Process for regenerating blixing solution for color photographic processing

ABSTRACT

A process of regenerating a blixing solution used in color photographic processings by suppressing the silver ion concentration in the solution to a low level, make up components being added to the blixing solution after processing as necessary.

United States Patent [1 1 Shirasu et al.

[451 Sept. 23, 1975 PROCESS FOR REGENERATING BLIXING SOLUTION FOR COLORPHOTOGRAPHIC PROCESSING Inventors: Kazuo Shirasu; Sachio Matsushita;

Tadao Hatano; Haruhiko lwano, all of Kanagawa, Japan Assignee: FujiPhoto Film Co., Ltd., Minamiashigara, Japan Filed: Oct. 18, 1972 Appl.No.: 298,712

Foreign Application Priority Data Oct. 22, 1971 Japan 46-83790 us. Cl96/60 BF; 96/22; 96/50 A;

V 96/55 m. cm G03C 1/32; 603C 5/26 Field of Search 96/50 A, 60, 61 M, 60BF, 96/61 R, 66.1. 66 R. 48 QP. 55; 210/190, 59.

[56] References Cited UNITED STATES PATENTS 3.241966 3/1966 Heilmawn eta1. 96/60 BF 3.620.725 11/1971 Kosta 96/22 3.634.088 10/1972 Cooley96/60 BF 3.706.561 12/1972 Mowrey ct a1v 96/60 BF PrimaryExaminen-Norman G. Torchin Assistant E.\'aminerAlfonso T. Suro PicoAttorney, Agent, or Firm-Sughrue, Rothwell. Mion. Zinn & Macpeak 14Claims, No Drawings PROCESS FOR REGENERATING BLIXINO SOLUTION FOR COLORPHOTOGRAPHIC PROCESSING BACKGROUND OF THE INVENTION 1. Field of TheInvention:

The present invention relates generally to processing photographicmaterials. in particular. blixing color photographic light-sensitivematerials. More particularly. the invention relates to regenerating aused blixing solution for reuse in color photographic processing.

2. Description of The Prior Art:

The combination of bleaching and fixing in photographic processing hasbeen known for a long time. that is. where both bleaching and fixing areconducted simultaneously in processing a silver halide photographicmaterial.

The necessary components for a blixing solution are one or morebleaching agents which oxidize the metallic silver of a silver image andone or more fixing agents which dissolve both undeveloped silver halideand the silver halide formed by the oxidation of the developed silver bythe bleaching agent. Various formulations for blixing solutions havebeen known in the field of photography. but a blixing solution using acombination of a ferric salt of an aminopolycarboxylic acid as theblcachingagent and a thiosulfate as the fixing agent is most usedbecause of its stability. high reaction rate and ease of handling.However. a blixing composition comprising a thiosulfate and a ferricsalt of an aminopolycarboxylic acid is comparatively expensive andfurther it must be discarded after use since no acceptable regenerationmethod therefor exists. disadvantages to the industrial utilizationofblixing solutions of this type.

Although it has been known to regenerate used bleaching solutions orfixing solutions for reusee. known regneration processes areinapplicable to the regeneration of the aforesaid blixing solution. Forinstance. a ferricyanide-containing bleaching solution may beregenerated by treatment with bromine as dcscribed in the specificationof 15.5. Pat. No. 2.515.930; by treating with a bromine releasingreagent in an aqueous solution as described in the specification of U.S.Pat. No. 2.61 1.699 and the specification of U.S. Pat. No. 2.6] 1.700;or by treating with a water-soluble persulfate as described in thespecification of U.S. Pat. No. 2.944.895. A used fixing solution can bereused by re moving all or a part ofthe silver from the fixing solutionand adding components to the fixing solution necessary to provide theoriginal formulation. Such a process is disclosed in the specificationsof U.S. Pat. Nos. 1.446.405. 1.527.942. and 3.082.079.

However. it is undesirable to regenerate a blixing solution of the typeindicated above with bromine or a persulfate because while such reagentsaccomplish the desirable oxidation of ferrous ions in solution. they atthe same time oxidize thiosulfate ions into sulfate ions or otheroxidation product ions. whereby the fixing faculty of the solution isdegraded. Accordingly. when such a blixing solution is used in aconventional system. the blixing solution must be discarded after onlyone use. which results in an economic loss as well as causing waterpollution problems.

To overcome these difficulties. a bleaching solution regenerationprocess has been proposed in Japanese patent application laid open topublic inspection No.

781/71. The regeneration process is fora used blixing solutioncontaining a ferric salt of aminopolycarboxylic acid as a bleachingagent and a thiosulfate as a fixing agent together with silver complexions and ferrous ions in the blixing process. At least a part of thesilver ions is removed from the blixing solution and oxygen isintroduced into the blixing solution in an amount sufficient to convertthe ferrous ions into ferric ions. whereby the oxidation potential ofthe blixing solution is recovered without losing the thiosulfate. andthus the blixing solution is brought into a reusable state.

According to the above process the desirable oxidation of ferrous ionsinto ferric ions to some extent can be conducted. thus the solutionbecomes reusable. the contamination problem can be solved. and furtherthe processing cost can be reduced. However. such a conventional processis accompanied by various faults and thus is hardly an excellentprocess. That is to say. according to the aforesaid process at least apart of the silver ions is removed in some manner before the ferrousions are oxidized by oxygen into ferric ions. but the removal of silverions encounters. in general. technical and practical difficulties. Forinstance. in the case of removing silver ions by the addition of sodiumsulfide. it is necessary to critically control the amount of sodiumsulfide added to prevent the formation of sulfide stains. and further itis difficult to maintain the pH value constant. Accordingly. such aprocess will not be practically employed in many color laboratories.

Furthermore. in the case of recovering silver ions from the used blixingsolution by electrolysis. the cost of equipment is large due to the lowcurrent efficiency. and it is also difficult to maintain theelectrolysis conditions constant. Accordingly. such a process will alsonot be practically employed in many color laboratories.

Therefore. the only practical process of this type is the processwherein. as clearly stated in the abovemcntioncd patent application.silver ions are removed by bringing the deteriorated blixing solutioninto contact with metallic iron to cause a replacement reaction.However. this process is not satisfactory in every case since althoughsilver ions may be removed by the contact of the blixing solution withmetallic iron. the ferric salt is at the same time reduced into theferrous salt. and thus a strong oxidation becomes necessary in order tooxidize all of the ferrous salt for recovering the activity of theblixing solution as a bleaching solution. Therefore. it is necessary touse a particularly effective oxygen mixing means or oxidation must beconducted for a long period of time.

A further fault in such a process is that since metallic iron isoxidized and dissolved in the solution. the concentration of iron ionsvaries during the repeated practice of the regeneration of the blixingsolution and thus it is very troublesome to control at stable concentrations iron ions in the blixing solution.

It is also inevitable in conventional processes that some part of theexpensive blixing solution will be lost during preventing the increasein iron salt concentration since it is difficult to completelyregenerate the blixing solution.

SUMMARY oF THE INVENTION One object of this invention is. therefor. toprovide a process for the regeneration ofa usedblixing solution whichcan be practiced in an economical. simple. and stable manner withoutbeing "accompanied by the aforesaid disadvantages of the prior art. 5

Another object of this invention is to provide a color photographicprocessing systemin which an expensive blixing solution can berepeatedly used in a simple manner.

Yet another object of this invention is to provide a color photographicprocessing system which gives no or less water contamination orpollution. problems caused by the used blixing solution.

According to the present invention. there is provided a process in whicha used blixing solution'can be regenerated by keeping the silver ionconcentration in' the blixing solution at processing to a low level,which does not lead to difficulties such as a decrease in' bleachingrate. wherein a small amount of make up (deficient) components are addedto the blixing solution to recover the original composition of theblixing solution without the necessity of removing silver ions and thuswithoutthe necessity of intentionally oxidizing the ferrous ions byoxygen. I

' DETAILED EXPLANATION OF THE INVENTION The silver ion concentration ina blixing solution may be kept below a certain level by employing afixing bath prior to the blixing process. whereby the greater part ofthe soluble silver salt is dissolved in the fixing bath to prevent alarge accumulation of the silver salt or silver ion in the blixing bathduring the subsequent blixing step. or alternatively by reducing theamount of silver salts incorporated in the photographic light-sensitivematerial. whereby the accumulation of an undesirable level of silverions in the blixing bath at processing is prevented. Ordinarily, whenthe amount of silver used in a silver halide photographic material isless than 2 g/m, the accumulation of silver ions to an extent which hasa harmful influence on blixing can be prevented without fixing. Morepreferably, the amount is less than L6 glm and most preferably it is inthe range of l.() l.5 g/m to insure long term operation.

Ifthe accumulation of silver ions to an extent that has a bad influenceon blixing can thus bc, prevented. the procedure of bringing the usedblixing solution into contact with metallic iron to remove silver in thesolution becomes unnecessary. Furthermore because the concentration ofthe ferrous ions in the blixing solution converted from the ferric ionsduring the oxidation of the developed silver is minor as compared withthe total amount of the ferric ions. the introduction'of oxygen into theused blixing solution toregenerate the same becomes unnecessary. In theprocess disclosed Japanese patent application laid open to publicinspection No. 781/71, ferrous ions are oxidized into ferric ions byintentionally introducing oxygen into the used blixing solution toconvert the ferrous ions into ferric ions at the same time that theblixing solution is brought into contact with metallic iron to removesilver ions.

It can generally be said that acceptable results are obtained so long asthe amount of silver ions present in the blix bath is maintained belowabout l() g/ I. more preferably below 5 g/ 1. Maximum efficiency ofblixing is obtainetf'when the amount of silver is maintained below 3 g/l.

The coated amount of silver halide for normal silver halide photographicelements is 2.0 to about l0 g/m For example: i l

Color paper 2.0 25 g/m" (.olor positive film 3.0 3.5 g/m' (for movies)('olor negative film 4.0 It] glm Accordingly. when treating the abovesilverhalide elements by the method of the present invention. a fixingstep must be carried out before blixing.

The blixing solution to which the .process of this invention is appliedis a solution containing a fixing agent diaminotetraacetic acid.ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid,ethyleneglycol bis(aminoethylether)tetraacetic acid. diaminopropanoltetraacetic' acid. N-( Z-hydroxyethyl )ethylenediamine triacetic acid,cthyliminodopropionic acid, and the like. Other bleaching agents usefulin the present invention are disclosed in US. Pat. No. 3,582,322.

The ferric salt of an amino'poly carboxylic acid used in this inventionmay be a ferric salt wherein all of the cations are ferric ions or itmay be a ferric salt where at least one carboxyl group is bonded to acation other than an iron ion, such as ammonia or an alkali metal ion. Aprefered example of such a ferric salt is sodium ferric ethylene'diaminetetraacetic acid.

In the blixing solution used in this invention. bleaching agents otherthan those listed may be used above. such a polyanimine cobalt complexsalt such as tetramminecarbonate cobalttlll) nitrate, quinones. or asimple water-soluble iron salt, e.g., ferric chloride. Moreover, besidesthe aforesaid ferric salts, a nonchelated salt of an aminopolycarboxylicacid such as a tetrasodium salt of cthylenediamine tetraacetic acid mayalso be used. e

The fixing agent and the bleaching agent indicated above are thenecessary components for the blixing solution to be used in the processof this invention. However. the blixing solution of this invention mayfurther contain other additives generally known in this area of the artas additives for ordinary blixing solutions e.g.. the blixing solutionmay contain a water-soluble thiocyanate such as ammonium thiocyanate.sodium thiocyanate. or potassium thiocyanate. or a silver halide solventsuch as ammonium bromide. an alkali metal bro mide, an amine, a sulfite.and mercaptazoles such as 2.5-dimercapto-thiadiazole andmercaptotriazole.

The concentration ofthe thiosulfate in the blixing solution is generallyabout 5 to about 200 g/liter and the concentration of the ferric salt ofthe aminopolycarboxylic acid is generally about 5 to about 200 g/liter.

Typical examples of such a blixing solution are disclosed in German Pat.No. 866,605; British Pat. No.-

l M14396; and German Pat. No. 966.410. Other examples of the blixingsolution are illustrated in the color developing processings designatedby main photographic cotnpanies in Europe as described on pages 122-] 23and l'lo of The British Journal of Photography". i960.

During the use of the blixing solution. silver ions are formed. and ifthe silver ions are accumulated in the blixing solution in a highconcentration. the blixing rate is reduced. For instance. the blixingrate of the com pletely blackened portion of a silver halide colorphotographic material (the blackened portion consisting of mixedcrystals of about 0.5% silver iodide and 995% silver bromide) changeswith a change in the silver ion concentration in the blixing solution asshown below:

Silver ion Blixing time ()xidation-retluction concentration potential(g/lilur) (mv vs SCE) O 4 min. sec. 8 2 min. '15 sec. (it) 5 8 min. sec.92 X l'. min. ll] secv I33 (The composition of the blixing solution usedin the above test was same as the composition described in 'Example I Aswill be understood from the above table. when reuse ofthe blixingsolution by adding deficient compo- Therefore. if fixing of the silverhalide photographic material is conducted prior to blixing. the amountof silver carried in the blixing solution is about At to about U) of thetotal amount of silver. and thus even in the case of processing alight-sensitive material containing a large amount of silver e.g.. aboutl0 g/m such as a color photographic negative film. the average silverion Iconcentration'in the blixing solution at processing is at ,amostabout 4 g/liter. which amount will not have a harmful influence onblixing processing.

. The absolute amount of silver thus entering the fix both (and then theblix bath) is thus seen to be about 2.0 g/m of material processed.

When color photographic light-sensitive materials :having a silvercontent of 1.5 g/m" are exposed. developed and blixed without fixingbetween development and blixing. the average silver ion concentration ofthe .sensitive materials. Since a color photographic paper usually hasonly a small amount of silver coated thereon. the latter process isconvenient.

The silver ions carried in washing water after blixing or the silverions formed in the fixing bath employed prior to blixing can be easilyrecovered by known processes. cg. electrolysis.

During the use of the blixing solution. the solution is diluted withwater carried by the photographic materials being processed. andnecessary chemicals are consumed and by-products are formed as a resultof reac tion in the processing. Accordingly. chemicals are added to theblixing solution to compensate for deficient components. According tothe process of this invention it is unnecessary to forcibly introduceoxygen into the blixing solution and thus the occurence of ex cessiveoxidation is less. Therefore. the oxidation of sulfite as well as theaccumulation of sulfate are lssened. which makes the control andmaintenance of the concentration of the blixing solution easy. Furthermore. due to the lowered accumulation of by-products. it becomesunnecessary to dispose ofa part of the overflow solution in theregeneration step. and thus the blix ing solution can be regeneratedcompletely or the total amount of the blixing solution can beregenerated and reused.

The amount of the deficient components to be added to the blixingsolution depends upon the kind of photographic lightsensitive material.the kind of developing machine. and the developing conditions. but astable processing is possible under each condition.

As mentioned above. the feature of the process of this invention is inthe point of reducing the amount of silver to be blixed in the blixingoperation but modifications of this invention to adopt the same to otherprocessings and other photographic light-sensitive materi als than thosedescribed above will easily be made by persons skilled in the art.Therefore. the following discussion should not be taken as restrictiveof the process of this invention.

The color developing solution used in combination with the process ofthis invention can generally be se lected from any of those used in.color photographic processings known to the prior art. and is generallyan aqueous alkaline solution of an aromatic primary amine colordeveloping agent containing. preferably. benzyl alcohol. Examples ofsuch color developing agents are phenylenediamine derivative such asN.N- diethyl-p-phenylenediamine sulfate and other known aromatic primaryamine color developing agents such as4-amino-N-ethyl-N-Bhydroxycthylaniline sulfate.3-methyl-4-amino-N-ethyl-B- methanesulfoamideethylaniline sesquisulfatemonohydrate. 3-methyl-4-amino-Nethyl-N-B- hydroxyethylaniline sulfate.3-methyl-4-amino-N.N- diethylaniline hydrochloride. and the like. Thecolor developing solution can further contain a sulfite. an alkali metalcarbonate. a bisulflte. a bromide. an iodide. an antifoggant. adeveloping accelerator. and a solvent such as diethylene glycol.

During the practice of the process of this invention. blixing isconducted after color development. and the techniques for reducing thesilver amount to be blixed are applied. After blixing in this invention,the color photographic material thus processed may be processed. ifnecessary, in an image stabilization bath. Of course. in addition to theabove fundamental steps conventional subsidiary baths such as a washingbath. a stopping bath. a hardening bath. a post-processing bath. analdehyde neutralizing bath. etc.. may be added. if desired. between theaforesaid fundamental steps according to the nature of the colorphotographic materials to be processed. Furthermore. in the ease ofapplying the process of this invention to a reversal color development.a black and white development as a matter of course. conducted prior tocolor development.

The color photographic light-sensitive materials to be procesed by theprocess of this invention contain in the silver halide emulsion layersat least one type of a four equivalent coupler or a two equivalentcoupler. Exemplary of four equivalent couplers as may be used in thepresent invention are those represented by the formula wherein Rrepresents a substituted or unsubstituted alkyl group. a substituted orunsubstited aryl group. or a substituted or unsubstituted heterocyclicgroup and R' represents an alkyl group. a carbamyl group. at aminogroup, or an amide group. 1

Specific examples of such four equivalent couplers are shown below:

l-p-sec-amylphenyl-3-n-amyl-5-pyrazolone.

2-cyanoacetyl-5-(p-sec-amylbenzoylamino)cou marone. 2-cyanoacetyleoumaron'e-5-( N-n-amyl-p-- amylsulfoanilide).2-cyanoacetylcoumarone-S-sulfone-N-nbutylanilide.l-p-laurylphenyl-3-methyl-5-pyrazolone.l-,8-naphthyl-3-amyl-5-pyrazolone.l-p-nitrophenol-3-n-amyl-5-pyrazolone.l-phenyl-3-acetylamino-5-pyrazolone. l-phenyl-3-n-valeramino-S-pyrazolone. l-phenyl3Z-chloroaceatylamino-S-pyrazolone, l-phenyl-3-(m-aminobenzyl)-amino-5-pyrazolonc. lp-phen0xyphenyl- 3-(p-t-amyloxybenzoyl )amino-S-pyrazolone, l-(2,4'.6-trichlorophenyl)-3-benzamido-5- pyrazolone.l-(2,4-dichlorophenyl)-3-[3"(2,4-di-tamylphenoxyacetamido)benzamido1-5-pyrazolone. and l-(2.4-dimethyl-6-chlorophenyl )-3-[3"-( 2", 4"-di'-t-amylphenoxyacetamido)benzamido1-5- pyrazolone.

In addition, the four equivalent couplers described in thespecifications of British Pat. No. 1.142.553 and US. Pat. No. 3,337,344are representative of couplers as may be used in the color photographicmaterials processed by the process of this invention.

Examples of four equivalent couplers giving yellow dyes such asbenzoylaeetoanilide typc dyes and pivaloylacetoanilide type dyes are theyellow couplers disclosed in the specifications of British Pat. No. L]l3.()38 and U.S.Pat. No. 3.337.344. Furthermore, the following yellowcouplers may also be employed for the above purpose:

a-{3-[a-(m-pcntadecylphenoxy)butylamidolbenzoyl}-2-chloroacetoanilide.

methoxyacetoanilide.

a- {3-[a-( 2.4-di-t-amylphenoxy )butylamidalbenzoyll'-2-chloroacetoanilide.2-chloro-3-[2.4-di-t-amylphenoxy)butylamido1benzoylacetoanilide.a-{3-[oz-(2.4-di-t-amylphenoxy)acetamidolbenzoyl} benzoylacettmnilide.and a-pivalyl-Z.5-dichloro-4-I N'-( n-octadecyl )-N-methylsulfamyl]-acetoanilide.

The above couplers are only exemplary of the four equivalent couplerswhich maybe incorporated in the silver halide emulsion layers of colorphotographic materials to be processed by the process of this invention.and the invention is not to be construed as limited thereto.

Examples of two equivalent couplers as can be used in the colorphotographic materials processed by the process of this invention areshown in the specification of U.S. Pat. No. 3.582.322. along withadditional useful four equivalent couplers and developing agents.

The process of this invention can be applied to processing silver saltcolor photographic materials in general. such as color negative films.color papers, color positive films. color reversal cinne films, andcolor reversal TV films.

Therefore. the types of silver halide and protective colloids used inthe color photographic light-sensitive materials to be processed in theprocess of this inven- EXAMPLE 1 A commercially available color paper*,was processed according to the process of this invention using a smallautomatic developing machine.

*(LP 8905-Type color paper. made by Fuji Photo Film Co.. Ltd.

The developing steps employed in this example were as follows:

Color development 24C. 6 min. Stop l'ixing 2 min. Water washing 2 min.lilixing 2 min. Water washing 2 min, Oxidation 2 min. Water washing 2min. Stabilization 2 min. Drying The compositions of the processingbaths used in the above steps were as follows:

Color developing solution: Benzyl alcohol Dicthylene glycol Sodiumhydroxide Sodium sull'ite Potassium bromide Sodium chloride BoraxHydroxylamine sulfate lithylenediamine tetraacetic acid 4-/\mino-3-methyl-N-ethyl-N-(B- re oo rn riuarrrnmo:

Continued sull'oneamidoetliyl )anilinc sesqui sulfate monohydrate 5.0 gWater added to make 1 liter. Stop l'i\int solution:

Sodium tliiosullate 70 g Ammonium tliiosulfate I700 30 cc Sodium acetateg Acetic acid 30 cc Potassium alum )5 g Water added to make I liter.lllising solution:

Sodium l'erric eth \'lenediamine tetraacetic acid monohydrate 33 gZ-Sodium ethylenediamine tetraacetate dihydrate 2 g Sodium carbonatemonoh \'drate l7 g Sodium sullite 5 g 70'/: Aqueous aounoniumthiosull'ate solution Boric acid The pH of the solution was adjusted to5.5. and then water was added thereto to make the total volume oneliter.

The fresh blixing complementary solution, the use of which will later bedescribed. had the following composition:

Sodium ferric eth \'lenedi-.imine tetraacctic acid monohydrate 40.5 g lSodium etltylenediaminc tetraacetate dihydratc i g Sodium carbonatemonoh \'drate 24 g Sodium sullite X g 70'.) Aqueous ammoniumthiosull'atc solution I50 ml ltorie acid It) g The pH of the fressblixing complementary solution was adjusted to 5.4. and water was addedto make the total volume one liter.

The processing treatments described above were continuously carried outusing the compositions de scribed above while complementary make upsolutions were added to the tanks of the machines as necessary inaccordance with prior art techniques except for the blixing solution,which was specially treated as described below. i

In the blixing step. a complementary blixing solution was continuouslyreplenished to the blixing solution tank at rate of900 ml for every Im'-' of color paper processed. As the starting complementary solution,liters ofthe fresh blixing complementary solution shown described abovewas employed. By the replenishments.

blixing solution in the same amount as the replenished solution addedcontinuously overflowed from the tank.

The overflowed solution was stored in a collection ation. which was thenreplenished at the same rate as above.

The composition of the first complementary solution was then the same asthe fresh complementary solution as shown in the following table.

Additive for Amount per Amount of the first regeneration liter ofovereomplementanv solution flow solution for regeneration (analyzedvalues) Sodium ferric (g) eth \'lenediamine )0 40.5 g!) tetraacetatemonohydrate Disodium ethylenediamine tetraacetate [.0 3.0 g/l dihydrateSodium carbonate hydrate 8.0 24 g/l Sodium ammonium 36 I50 ml/liter as alltiosttllltte aqueous solution olammonium thiosullate Boric acid 3 l0.0g/l pH 5.40

The same operations of storing the overflow solution. adding theadditives for regeneration and then replenishing the complementarysolution for regeneration were constantly repeated during theprocessing. During the operation. when the total atnount of thereplenished solution was the same as the volume of the tank (in otherwords. when one round was terminated). the blixing solution in the tankwas sampled and analyzed. The results obtained are as follows:

Concentration of Components in Solutions Sampled Round no. AnalyzedComponents A I! D F.

(all) (g/l) (ml/I) (g/l) (all) I 35.0 0.08 0.03 (H4 2 34.) 0.68 HH 0.26L20 3 3(1.) l.2l 101 0.47 2.12 4 37.2 L68 I02 0.64 2.91 S 38.0 209 I020.79 3.62 h 38.8 2.45 I03 0.93 4.24 7 38.5 2.75 I03 [.05 4.72 It 40.)3.02 I03 l.l5 5.24 9 40.6 3.26 I04 1.24 5.64 l() 4L0 3.48 104 1.32 5.99I) 4L4 3.64 I05 1.39 6.37 12 4L8 3.80 I05 1.45 6.58 13 42d 3.90 [05 1.50\Ll'il l4 42.4 3.95 1.54 7.0) I5 4211 4.00 105 1.58 7.20 20 43.4 4.05I06 [.70 7.80

A: The total iron salts of ethylenediamine tetra-acetic acid (as sodiumt'errii: cthylcncdiamine \ctracetic acid monoliydratc).

I): Sodium l'crrous etliylenediamine tetraacetic acid.

(z Thiosullates tas 70'; ammonium salt solution).

I). Silver salts (as Ag).

Ii: Sulfate radicals (as NtuSOJ As shown in the above table. thecomposition of the solution gradually approached steady state as thenumber of rounds the solution was used increased. and no significantchanges in composition occurred at the 20th round. At this round. theaccumulated amount of by products was slight with respect to sulfateradicals. ferric ethylencdiamine tetraacetate. and silver salt. andfurther the reduction in blixing rate was so slight (e.g.. the period oftime required for finishing blixing was about 85-90 seconds when thesolution in the tank at the 20th round was used. while the period oftime in the ease of using a fresh complementary solution was 75 seconds)that the accumulated solution in the tank could be used repeatedly inblixing for the blixing period of I20 seconds defined for the developingmachine.

The necessary components of the blix bath and the replenishing solutionare the bleaching agent and the fixing agent. Other components areoptional. l

The amounts of the bleaching agent and the fixing agent in the blixingbath have been heretofore de scribed (about 5 to about 200 g/liter foreach). The amount of these components in the replenishing solution isusually about 1.0 to about 1.6 times by weight the amount in the blixingbath. Obviously. it is preferred to at least return the blix bath to itsoriginal strength.

The volume of the replenishing solution added is generally from about200 to about 1250 cc/m" of material processed. preferably 500 800 cc/mIt will be clear to one skilled in the art, however. that values outsideof the above ranges can be used if one is willing to suffer. someinefficiencies in the blixing or regeneration.

It has been confirmed that by conducting such a regeneration process:(1) the amount of chemicals used in the process is reduced to A; to ofthat in the case of not conducting the regeneration;(2) the watercontamination due to waste solution disposal from the developing machineis reduced (that is to say. the BOD and COD as well as the heavy metalscontent are reduced); and (3) the process is advantageous as comparedthe process described in Japanese patent application open to publicinspection No. 781/71 as shown below.

For purposes of comparison the process was conducted using the same kingof color paper as was used in the above process while omitting thestop-fixing step.

The overflow solution of the blixing solution was introduced into acartridge filled with metallic iron wool.

Two such cartridges were connected in series. The solution from thecartridges contained ferrous ions formed from the complete reduction offerric ions. The solution was introduced into an aeration tank equippedwith an air sparger and air was blown into the solution for about onehour. By the aeration the ferrous ions were converted into ferric ions.the solution changing dark red. At the same time it was confirmed thatthe oxidation reduction potential of the solution had been recovered.Deficient components (make up components needed to regenerate thesolution) such as disodium ethylenediamine tetraacetate dihydrate.sodium ammonium thiosulfate. sodium sulfite. sodium carbonate. and boricacid were added to the solution to provide a complementary solution.which was reused.

By repeating the above operation. the process was conducted for 50 days.However. on comparing this process with the process of our invention. weconfirmed that. the process of our invention is superior to the aboveprocess in the following points:

1. In the process of this invention silver removal and air blowing areunnecessary and it is only necessary to add deficient components forregeneration. That is to say. the process ofour invention is quitesimple and can be easily conducted. On the other hand. the comparisonprocess as shown above requires a long period of time for regeneration.as well as cartridges and an aeration tank. which makes the conventionalprocess disadvantageous as compared with the process of our invention. I

2. In the comparison process the blixing rate is greatly reduced if theaeration is insufficient due, perhaps. to the presence of a large amountof ferrous ions.

On the other hand. aeration is unncessary in the process of ourinvention and thus the process of our invention is not accompanied bythe aforementioned problems.

3. If. on the other hand. aeration is conducted sufficiently in thecomparison process. in addition to the oxidation of ferrous ions.significant oxidation of sulfite oxxurs as a side reaction. and thus alarge amount of sulfite is required as an additive for regeneration. Theprocess of our invention is not accompanied. by such problems based onthe oxidation of sulfite.

4. In the comparison process. iron was dissolved in the solution fromthe steel wool in the cartridge. and when the regeneration process wasrepeatedly conducted the concentration of iron salt increased rapidly.and could not be maintained constant. In this case problems such as theprecipitation of iron salt and the formation of brown stains on thecolor paper oceured. In order to solve those problems. it was necessaryto increase the amount of ethylene diamine tetraacetate added forregeneration and to discard about 20% of the overflow solution duringeach regeneration operation. Accordingly. in the comparison process. theamount of chemical consumed becomes layer. which makes the processdisadvantageous as compared with the process of this invention. Thecomparison process is also disadvantageous from the point of causingcontamination, and further it is difficult to control the amount of theoverflow solution discharged.

5. When the comparison process was conducted without dischargingoverflow solution. the process became inoperable in only three rounds.

6. Because the dissolution rate of thesteel wool was high. the amount ofoverflow solution which could be processed using 1 kg of steel wool inthe comparison process was only 200 liters. Although iron is anexpensive metal. such a high rate of iron consumption isdisadvantageous.

As mentioned above. while the comparison process illustrated aboveincludes various faults. the process of the present invention is asimple, convenient and stable process which is not accompanied by suchfaults.

The process of the present invent-ion requires a stopfixing step in oneembodiment, but the addition of such a step is a very slightdisadvantage as compared to the above-mentioned various advantages ofthis invention. Furthermore. in the process of this invention. silvercan be recovered in the stop fixing process and during water washing.andthus the'efficiency of silver salt recovery can be maintained at ahigh level.

EXAMPLE 2 A color negative film comprising a sensitive silver halideemulsion layer containing gelatin and silver iodobromide on a celluloseacetate film (coated silver amount of 9.2 g/m) was processed in a smallautomatic developing machine according to the process of this invention.The processes employed in this example were as follows: v v

Processing step:

Color development 14C l2 min. Stopping 4 min. Hardening fixing 4 min.Water washing 4 min. Blixing 6 min. Water washing 4 min. Post processing8 min.

-Continued Water washing X min.

Drying The compositions of the processing baths used in the aboveprocessing steps were as follows: It

('olor developing solution: Bemyl alcohol cc I Sodium hydroxide [1.5 gDiethylene glycol 3 cc ll) Sodium hexametaphosphate 2 g Sodium sullite 2g Potassium brotnide 2 g 4'Amino-Z-methyl-N-ethy|-B hydroxyethylanilinesesquisulfate monohydrale 5 g Metaboric acid ()5 g Navox (Sodiummetaborate) 77 g Water to make to one liter. Stopping solution: Sodiumacetate 30 g Glacial acetic acid 8 ml Water to make one liter. Hardeningfixing bath: Sodium hexametaphosphate l g Sodium sulfite 5 g Sodiumthiosulfate I50 g Sodium acetate 20 g Acetic acid ti ml Potassium alum[5 g 7 Water to make one liter. Blixing bath: Sodium ferricethylenediaminc tetraaeetic acid monohydratc 33 g Z-Sodiumetliylenediamine tetraacctic dihydrate 2 g BUItIXlOH O 5 g Boric acid H)g Sodium sulfite 5 g 70% Aqueous ammonium thiosulfatc lfitl ml soln.'l'hiourca 5 g pH adjusted to 6.0 Water to make one liter.

The amount of each component in the complementary solution for blixingwas l.5 times the amount of each component in the flixing solution.

As in Example 1. the fresh complementary solution 40 was used in onlythe first round. and thereafter a complementary solution prepared byadding the additives necessary for regeneration to the overflow solutionwas used. The volume of the complementary solution per round was 20liters. 4g

the accumulated by-products was far below a level which would have aharmful influence when regeneration is repeated.

For the sake of comparison. the above experiment was followed whilereplacing the blixing bath in the above process by a hardening bathconsisting of an alkaline aqueous solution of formalin. thereby yieldinganother process outside the process of this invention. In thiscomparison experiment, silver salt rapidly accumulated in the blixingbath with an increase in the number of regeneration rounds. that is tosay. the amount of accumulated silver salt reached 7.5 g/liter at thesecond round. l4 g/liter at the third round. and 18 g/liter at thefourth round. Further. the content of ferrous ions was large. theblixing rate was low. and the removal of silver from the processedsample was imperfect.

As another comparison experiment. the above comparison experiment wasfollowed except the overflow solution of the blixing solution wasfurther passed through cartridges filled with steel wool and then aerated in an aeration tank by blowing air into the solution therein. Inthis experiment. the sample processed had good image qualities. butvarious disadvantages as shown in the comparison experiment in Example Iwere observed from the point of maintaining constant bath compositions.

EXAMPLE 3 This example shows that the process of this invention can beapplied directly, without conducting pre-fixing, to a light-sensitivematerial having a reduced amount of Amount per liter of over llowsolution Additive for regeneration First complementary solution forregene ration (analytical When the process of this invention wascontinuously conducted using the afore-indicated baths. the reaction wasfinished in a definite period of time without any unusual influence onthe qualities of the processed products and at a sufliciently highblixing rate. The compositions at the l()th and l5th rounds of theoperation were as shown below. illustrating that the amount of silvercoated thereon. That is to say. developing processings the same as inExample l were conducted using color papers having coated silver amountsof L56 g/m and 3.12 glm respectively. in this case. however. fixingbefore blixing was omitted.

The concentration of each component changed during continuouslyrepeating the regeneration process in the same manner as in Example 1.except the concentration of silver salt. The changes in theconcentration of silver salt are shown in the following table:

Concentration of silver salt lg/l 1n the blixing step. the initialblixing time was 75 seconds for the color paper having silver coated inan amount of 1.56 g/m which was increased about to 105 seconds at the thround. However. blixing was finished in a definite period of time andgood results were obtained. On the other hand. in case of using colorpapers having silver coated in an amount of 3.12 g/m the initial timerequired for finishing blixing was 90- 100 seconds, and further theblixing time increased rapidly while repeating the processing cycle,whereby blixing became insufficient. In other words, when the amount ofsilver in the color papers was reduced, the blixing rate for the colorpapers was high and the accumulation of silver salt in the blixingsolution repeated regenerations was low, which makes the application ofthe process of this invention possible.

EXAMPLE 4 The same continuous regeneration process as in Example l wasfollowed using a Noritsu-type Four-File Paper Automatic DevelopingMachine (made by Noritsu Koki K. K.) and commercially available CLP8905-Type color paper (made by Fuji Photo Film Co.) for 2 months. Thedeveloping machine was equipped with an air sparger in the blixing tankto assist the agita tion of the solution in the tank. and one second airbursts were made at a rate of once every 10 seconds.

The results of the development were good. the change in composition ofthe blixing solution showing almost the same tendency as in Example 1.but the amount of accumulated ferrous salt in the tank was about /2 ofthe amount in the case of Example l. Thus. it will be understood thatthe combined use of an air sparger and the process of this invention isone prefered embodiment of this invention.

While the invention has been described in detail and with reference tospecific embodiments thereof. it will be apparent to one skilled in theart that various changes and modification can be made therein withoutdeparting from the spirit and scope thereof.

What is claimed is:

l. In the blixing ofcolor photographic materials using a blixingsolution. an improved process of regenerating used blixing solutionwhich comprises:

maintaining the silver salt concentration. expressed in terms of theamou nt ft if silver ions. at level less than about LOg/Iiter iri' theblixing solution and thereafter adding components to the used blixingsolution to make up for those in the blixing processing without removingsilver salt from the used blixing solution. thereby providing acomposition at least equivalent to that of the blixing solution prior touse for blixing additional color photographic materials. wherein saidmaintaining is accomplished by subjecting the color photographicmaterials. after color development. to fixing prior to blixing topreliminarily remove a substantial portion of soluble silver salt fromthe color photographic materials or wherein said maintaining of theamount ofsilver salt is obtained by reducing the amount of coated silverin the initial color photographic materials to below 2.0g/m'-'.

2. The process as set forth in claim 1 in which said blixing solutioncontains (a) at least one member from the group consisting of a ferriccomplex salt of an aminopolycarboxylic acid. a cobalt (lll) complex saltof a polyammine. a cobalt (lll) complex salt of nitrous acid. and awater-soluble ferric salt as a bleaching agent; and (b) a thiosulfate asat fixing agent.

3. The process as set forth in claim 1 in which the color photographicmaterials are. after color development. subjected to fixing prior toblixing to preliminarily remove a substantial portion of soluble silversalt from the color photographic materials.

4. The process of claim 1 in which the maintaining is conducted byreducing the amount of coated silver in the initial color photographicmaterials to below 2.0g/m

5. The process of claim 2 wherein the blixing solution comprises ableaching agent and at fixing agent each present in an amount of fromabout 5 to about 200 g I of blixing solution. and components are addedto the spent blixing solution so as to maintain these ranges duringblixing,

6. The process of claim 3 wherein fixing is conducted so as to reducedthe amount of silver carried into the blixing solution to about A toabout 1/6 of the total amount of silver present in the colorphotographic material.

7. The process of claim 1 wherein the absolute amount of silver enteringthe blixing solution is less than about 2 g/m of color photographicmaterial processed.

8. The process of claim 5 wherein the components which are added to theblix solution to make up for those used in the blixing processing areadded in an amount of from 1.0 to 1.6 times the amount present in theblix solution. thereby at least maintaining the con centration of thecomponents in the blix solution.

9. The process of claim 8 wherein the components are added in an aqueoussolution at a rate of from about 200 to about 1250 cc/m of colorphotographic material process.

10. In the process of color photographic materials. an improved processof regenerating a blixing solution which consists essentially of:

a. maintaining the amount of silver salt expressed as silver ion reactedin the blixing solution at a value less than 10 g/l of blixing solution;

b. removing spent blixing solution from the blixing treatment andregenerating the spent blixing solution by adding thereto make upcomponents in an amount at least equal to the components of the blixingsolution consumed in the blixing operation to provide a composition atleast equivalent to that l7 oi the initial blixing solution composition.without removing silver salt from the blixing solution;

c. returning the regenerated blixing solution oi step (b) to thebiixingtreatment for the processing oi additional color photograhpicmaterials.

d. repeating steps (b) to) while observing the condition recited in step(a). wherein said maintaining is accomplished by subjecting the colorphotographic materials after color development. to fixing prior toblixing to preliminarily remove a substantial portion oi soluble silversalt from the color photographic materials or wherein said maintainingof the amount ofsilver salt is obtained by reducing the amount of coatedsilver in the initial color photographic materials to below 2.()g/m 11.The process ot'elaim 10 wherein the regenerated blixing solutionreturned to the blixing treatment contains from about 1.0 to about l.6times an amount of 18 bleaching agent and fixing agent present in theblising bath. on a unit volume basis. and the regenerated blixingsolution is returned to the blixing treatment in an amount of from about200 to about 1250 ce/m'- otcolor photograpi'iic material subjected tothe biixing treatment.

12. The process oiclaim ll wherein the blixing bath comprises from about5 to about 200 g I oi bleaching agent and from about 5 to about 200 g Ioi iixing agent.

13. The process oiclaim 10 wherein condition (a) is maintained by fixingprior to blixing.

14. The process of claim 13 wherein condition (a) is maintained byprocessing a color photographic material without fixing. which colorphotographic material initially contained coated silver in an amountless than 2.0 g/m.

1. IN THE BLIXING OF COLOR PHOTOGRAPHIC MATERIALS USING A BLIXINGSOLUTION, AN IMPROVED PROCESS OF REGENERATING USED BLIXING SOLUTIONWHICH COMPRISES: MAINTAINING THE SILVER SALT CONCENTRATION, EXPRESSED INTERMS OF THE AMOUNT OF SILVER IONS, AT LEVEL LESS THAN ABOUT 10G/LITERIN THE BLIXING SOLUTION AND THEREAFTER ADDING COMPONENTS TO THE USEDBLIXING SOLUTION TO MAKE UP FOR THOSE IN THE BLIXING PROCESSING WITHOUTREMOVING SILVER SALT FROM THE USED BLIXING SOLUTION, THEREBY PROVIDING ACOMPOSITION AT LEAST EQUIVALENT TO THAT OF THE BLIXING SOLUTION PRIOR TOUSE FOR BLIXING ADDITIONAL COLOR PHOTOGRAPHIC MATERIALS, WHEREIN SAIDMAINTAINING IS ACCOMPLISHED BY SUBJECTING THE COLOR PHOTOGRAPHICMATERIALS, AFTER COLOR DEVELOPMENT, TO FIXING PRIOR TO BLIXING TOPRELIMINARILY REMOVE A SUBSTANTIAL PORTION OF SOLUBLE SILVER SALT FROMTHE COLOR PHOTOGRAPHIC MATERIALS OR WHEREIN SAID MAINTAINING OF THEAMOUNT OF SILVER SALT IS OBTAINED BY REDUCING THE AMOUNT OF COATEDSILVER IN THE INITIAL COLOR PHOTOGRAPHIC MATERIALS TO BELOW 2.0G/M2. 2.The process as set forth in claim 1 in which said blixing solutioncontains (a) at least one member from the group consisting of a ferriccomplex salt of an aminopolycarboxylic acid, a cobalt (III) complex saltof a polyammine, a cobalt (III) complex salt of nitrous acid, and awater-soluble ferric salt as a bleaching agent; and (b) a thiosulfate asa fixing agent.
 3. The process as set forth in claim 1 in which thecolor photographic materials are, after color development, subjected tofixing prior to blixing to preliminarily remove a substantial portion ofsoluble silver salt from the color photographic materials.
 4. Theprocess of claim 1 in which the maintaining is conducted by reducing theamount of coated silver in the initial color photographic materials tobelow 2.0g/m2.
 5. The process of claim 2 wherein the blixing solutioncomprises a bleaching agent and a fixing agent each present in an amountof from about 5 to about 200 g / l of blixing solution, and componentsare added to the spent blixing solution so as to maintain these rangesduring blixing.
 6. The process of claim 3 wherein fixing is conducted soas to reduced the amount of silver carried into the blixing solution toabout 1/4 to about 1/6 of the total amount of silver present in thecolor photographic material.
 7. The process of claim 1 wherein theabsolute amount of silver entering the blixing solution is less thanabout 2 g/m2 of color photographic material processed.
 8. The process ofclaim 5 wherein the components which are added to the blix solution tomake up for those used in the blixing processing are added in an amountof from 1.0 to 1.6 times the amount present in the blix solution,thereby at least maintaining the concentration of the components in theblix solution.
 9. The process of claim 8 wherein the components areadded in an aqueous solution at a rate of from about 200 to about 1250cc/m2 of color photographic material process.
 10. In the process ofcolor photographic materials, an improved process of regenerating ablixing solution which consists essentially of: a. maintaining theamount of silver salt expressed as silver ion reacted in the blixingsolution at a value less than 10 g/l of blixing solution; b. removingspent blixing solution from the blixing treatment and regenerating thespent blixing solution by adding thereto make up components in an amountat least equal to the components of the blixing solution consumed in theblixing operation to provide a composition at least equivalent to thatof the initial blixing solution composition, without removing silversalt from the blixing solution; c. returning the regenerated blixingsolution of step (b) to the blixing treatment for the processing ofadditional color photograhpic materials; d. repeating steps (b) - (c)while observing the condition recited in step (a), wherein saidmaintaining is accomplished by subjecting the color photogrAphicmaterials after color development, to fixing prior to blixing topreliminarily remove a substantial portion of soluble silver salt fromthe color photographic materials or wherein said maintaining of theamount of silver salt is obtained by reducing the amount of coatedsilver in the initial color photographic materials to below 2.0g/m2. 11.The process of claim 10 wherein the regenerated blixing solutionreturned to the blixing treatment contains from about 1.0 to about 1.6times an amount of bleaching agent and fixing agent present in theblixing bath, on a unit volume basis, and the regenerated blixingsolution is returned to the blixing treatment in an amount of from about200 to about 1250 cc/m2 of color photographic material subjected to theblixing treatment.
 12. The process of claim 11 wherein the blixing bathcomprises from about 5 to about 200 g / l of bleaching agent and fromabout 5 to about 200 g / l of fixing agent.
 13. The process of claim 10wherein condition (a) is maintained by fixing prior to blixing.
 14. Theprocess of claim 13 wherein condition (a) is maintained by processing acolor photographic material without fixing, which color photographicmaterial initially contained coated silver in an amount less than 2.0g/m2.